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Search Results: 1 - 10 of 543 matches for " Tatyana Zvyagintseva "
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The Effect of Sulfated (1→3)-α-l-Fucan from the Brown Alga Saccharina cichorioides Miyabe on Resveratrol-Induced Apoptosis in Colon Carcinoma Cells
Olesia S. Vishchuk,Svetlana P. Ermakova,Tatyana N. Zvyagintseva
Marine Drugs , 2013, DOI: 10.3390/md11010194
Abstract: Accumulating data clearly indicate that the induction of apoptosis by nontoxic natural compounds is a potent defense against the development and progression of many malignancies, including colon cancer. Resveratrol and the fucoidans have been shown to possess potent anti-tumor activity in vitro and in vivo. The aim of the present study was to examine whether the combination of a fucoidan from the brown alga Saccharina cichorioides Miyabe and resveratrol would be an effective preventive and/or therapeutic strategy against colon cancer. Based on NMR spectroscopy and MALDI-TOF analysis, the fucoidan isolated and purified from Saccharina cichorioides Miyabe was (1→3)-α-l-fucan with sulfate groups at C2 and C4 of the α-l-fucopyranose residues. The fucoidan enhanced the antiproliferative activity of resveratrol at nontoxic doses and facilitated resveratrol-induced apoptosis in the HCT 116 human colon cancer cell line. Apoptosis was realized by the activation of initiator caspase-9 and effector caspase-7 and -3, followed by the cleavage of PARP. Furthermore, significant inhibition of HCT 116 colony formation was associated with the sensitization of cells to resveratrol by the fucoidan. Taken together, these results demonstrate that the combination of the algal fucoidan with resveratrol may provide a potential therapy against human colon cancer.
Anticancer and Cancer Preventive Properties of Marine Polysaccharides: Some Results and Prospects
Sergey N. Fedorov,Svetlana P. Ermakova,Tatyana N. Zvyagintseva,Valentin A. Stonik
Marine Drugs , 2013, DOI: 10.3390/md11124876
Abstract: Many marine-derived polysaccharides and their analogues have been reported as showing anticancer and cancer preventive properties. These compounds demonstrate interesting activities and special modes of action, differing from each other in both structure and toxicity profile. Herein, literature data concerning anticancer and cancer preventive marine polysaccharides are reviewed. The structural diversity, the biological activities, and the molecular mechanisms of their action are discussed.
Comparative Analysis of Glycoside Hydrolases Activities from Phylogenetically Diverse Marine Bacteria of the Genus Arenibacter
Irina Bakunina,Olga Nedashkovskaya,Larissa Balabanova,Tatyana Zvyagintseva,Valery Rasskasov,Valery Mikhailov
Marine Drugs , 2013, DOI: 10.3390/md11061977
Abstract: A total of 16 marine strains belonging to the genus Arenibacter, recovered from diverse microbial communities associated with various marine habitats and collected from different locations, were evaluated in degradation of natural polysaccharides and chromogenic glycosides. Most strains were affiliated with five recognized species, and some presented three new species within the genus Arenibacter. No strains contained enzymes depolymerizing polysaccharides, but synthesized a wide spectrum of glycosidases. Highly active β- N-acetylglucosaminidases and α- N-acetylgalactosaminidases were the main glycosidases for all Arenibacter. The genes, encoding two new members of glycoside hydrolyses (GH) families, 20 and 109, were isolated and characterized from the genomes of Arenibacter latericius. Molecular genetic analysis using glycosidase-specific primers shows the absence of GH27 and GH36 genes. A sequence comparison with functionally-characterized GH20 and GH109 enzymes shows that both sequences are closest to the enzymes of chitinolytic bacteria Vibrio furnissii and Cellulomonas fimi of marine and terrestrial origin, as well as human pathogen Elisabethkingia meningoseptica and simbionts Akkermansia muciniphila, gut and non-gut Bacteroides, respectively. These results revealed that the genus Arenibacter is a highly taxonomic diverse group of microorganisms, which can participate in degradation of natural polymers in marine environments depending on their niche and habitat adaptations. They are new prospective candidates for biotechnological applications due to their production of unique glycosidases.
Hydrolysis of Fucoidan by Fucoidanase Isolated from the Marine Bacterium, Formosa algae
Artem S. Silchenko,Mikhail I. Kusaykin,Valeriya V. Kurilenko,Alexander M. Zakharenko,Vladimir V. Isakov,Tatyana S. Zaporozhets,Anna K. Gazha,Tatyana N. Zvyagintseva
Marine Drugs , 2013, DOI: 10.3390/md11072413
Abstract: Intracellular fucoidanase was isolated from the marine bacterium, Formosa algae strain KMM 3553. The first appearance of fucoidan enzymatic hydrolysis products in a cell-free extract was detected after 4 h of bacterial growth, and maximal fucoidanase activity was observed after 12 h of growth. The fucoidanase displayed maximal activity in a wide range of pH values, from 6.5 to 9.1. The presence of Mg 2+, Ca 2+ and Ba 2+ cations strongly activated the enzyme; however, Cu 2+ and Zn 2+ cations had inhibitory effects on the enzymatic activity. The enzymatic activity of fucoidanase was considerably reduced after prolonged (about 60 min) incubation of the enzyme solution at 45 °C. The fucoidanase catalyzed the hydrolysis of fucoidans from Fucus evanescens and Fucus vesiculosus, but not from Saccharina cichorioides. The fucoidanase also did not hydrolyze carrageenan. Desulfated fucoidan from F. evanescens was hydrolysed very weakly in contrast to deacetylated fucoidan, which was hydrolysed more actively compared to the native fucoidan from F. evanescens. Analysis of the structure of the enzymatic products showed that the marine bacteria, F. algae, synthesized an α-l-fucanase with an endo-type action that is specific for 1→4-bonds in a polysaccharide molecule built up of alternating three- and four-linked α-l-fucopyranose residues sulfated mainly at position 2.
Fucoidans as Potential Inhibitors of HIV-1
Maria M. Prokofjeva,Tatyana I. Imbs,Natalya M. Shevchenko,Pavel V. Spirin,Stefan Horn,Boris Fehse,Tatyana N. Zvyagintseva,Vladimir S. Prassolov
Marine Drugs , 2013, DOI: 10.3390/md11083000
Abstract: The antiviral activity of different structure fucoidans (α-l-fucans and galactofucans) was studied using two model viral systems based on a lentiviral vectors and a replication competent Moloney murine leukemia virus (Mo-MuLV). It was found that investigated fucoidans have no cytotoxic effects on Jurkat and SC-1cell at the concentration range of 0.001–100 μg/mL. Fucoidans with different efficiency suppressed transduction of Jurkat cell line by pseudo-HIV-1 particles carrying the envelope protein of HIV-1 and infection of SC-1 cells by Mo-MuLV. According to our data, all natural fucoidans can be considered as potential anti-HIV agents regardless of their carbohydrate backbone and degree of sulfating, since their activity is shown at low concentrations (0.001–0.05 μg/mL). High molecular weight fucoidans isolated from Saccharina cichorioides (1.3-α-l-fucan), and S. japonica (galactofucan) were the most effective inhibitors.
SCREENWRITING FORECASTING OF SOCIO-ECONOMIC SYSTEMS’S DEVELOPMENT Сценарное прогнозирование развития социально-экономических систем
Nazarenko A. V.,Zvyagintseva O. S.
Polythematic Online Scientific Journal of Kuban State Agrarian University , 2012,
Abstract: The article describes the methodological approaches to screenwriting predicting complex economic processes based on the systemic nature of the study. This article presents some of the approaches to the construction of scenarios, such as the imitation modeling of economic processes and expert approach allowing obtaining long term scenarios based on global patterns of development
The Software for Constructing Trails with Local Restrictions in Graphs  [PDF]
Tatyana Panyukova, Igor Alferov
Open Journal of Discrete Mathematics (OJDM) , 2013, DOI: 10.4236/ojdm.2013.32017
Abstract:

The present research considers the problem of covering a graph with minimal number of trails satisfying the pre-defined local restrictions. The research is devoted to the problem of graph covering by minimal number of trails satisfying some local restrictions. Algotithm of allowed Eulerian cycle construction is considered. The authors showed that it is possible to recognize the system of transitions and solve the problem of constructing the allowable path by linear time. Its also possible to find allowable Eulerian cycle for Eulerian graph or to proclaim that such a cycle does not exist by the time O(|V(G).|E(G)|). All presented algorithms have the software realization.

Analysis of the Integral Efficiency Indicator for Information Systems of the Cyclic Type Accounting for Weights  [PDF]
Tatyana Yuldashevа, Juliya Doronina
Journal of Data Analysis and Information Processing (JDAIP) , 2013, DOI: 10.4236/jdaip.2013.12002
Abstract: The article is dedicated to the task of developing efficient means to analyze functioning of an information system of the cyclic type based on determining the integral performance criterion. We consider the subject area related to the analysis of moments of peak loads in teaching (admissions, conducting tests and examinations, accreditation of a university, etc.). The criterion is developed based on the analysis of all the processes occurring in the information system (IS) of a university and based on the selection of main factors affecting the change in the effective functioning of the university departments. Certain qualitative and quantitative parameters affecting the integral index of efficiency are considered at various times, since functioning of the whole system is cyclical. A weight for each criterion is accounted for in the integral indicator of efficiency. The proposed approach will allow for simplification of the research of efficiency characteristics of the information systems of the cyclic type based on the analysis of the integral coefficient.
An Extreme Value Analysis of Wind Speed over the European and Siberian Parts of Arctic Region  [PDF]
Alexander Kislov, Tatyana Matveeva
Atmospheric and Climate Sciences (ACS) , 2016, DOI: 10.4236/acs.2016.62018
Abstract: Multiyear observed time series of wind speed for selected points of the Arctic region (data of station network from the Kola Peninsula to the Chukotka Peninsula) are used to highlight the important peculiarities of wind speed extreme statistics. How largest extremes could be simulated by climate model (the INM-CM4 model data from the Historical experiment of the CMIP5) is also discussed. Extreme value analysis yielded that a volume of observed samples of wind speeds are strictly divided into two sets of variables. Statistical properties of one population are sharply different from another. Because the common statistical conditions are the sign of identity of extreme events we therefore hypothesize that two groups of extreme wind events adhere to different circulation processes. A very important message is that the procedure of selection can be realized easily based on analysis of the cumulative distribution function. The authors estimate the properties of the modelled extremes and conclude that they consist of only the samples, adhering to one group. This evidence provides a clue that atmospheric model with a coarse spatial resolution does not simulate special mechanism responsible for appearance of largest wind speed extremes. Therefore, the tasks where extreme wind is needed cannot be explicitly solved using the output of climate model. The finding that global models are unable to capture the wind extremes is already well known, but information that they are members of group with the specific statistical conditions provides new knowledge. Generally, the implemented analytical approach allows us to detect that the extreme wind speed events adhere to different statistical models. Events located above the threshold value are much more pronounced than representatives of another group (located below the threshold value) predicted by the extrapolation of law distributions in their tail. The same situation is found in different areas of science where the data referring to the same nomenclature are adhering to different statistical models. This result motivates our interest on our ability to detect, analyze, and understand such different extremes.
Reporting of results of interventional studies by the information service of the National Institutes of Health
Tatyana Shamliyan
Clinical Pharmacology: Advances and Applications , 2010, DOI: http://dx.doi.org/10.2147/CPAA.S12398
Abstract: rting of results of interventional studies by the information service of the National Institutes of Health Original Research (3341) Total Article Views Authors: Tatyana Shamliyan Published Date September 2010 Volume 2010:2 Pages 169 - 176 DOI: http://dx.doi.org/10.2147/CPAA.S12398 Tatyana Shamliyan Division of Health Policy and Management, University of Minnesota School of Public Health, MN, USA Abstract: The Food and Drug Administration Amendments Act of 2007 mandated that sponsors of applicable studies must provide results within one year of study completion. We aimed to analyze the factors associated with reporting of results from interventional studies registered on ClinicalTrials.gov. On May 20, 2010, we retrieved 20 available fields from 57,233 closed studies on the website and identified 31,161 interventional studies that were required to post results. We compared the proportion of studies with results versus studies without results by age, gender, and disease status of participants, by interventions, sponsors, phase of clinical trials, and completion dates. The results of studies were reported for 4.7% of applicable studies, 8% of industry-sponsored studies, 7.5% of Phase II and 6.5% of Phase IV clinical trials, 4.9% of drug studies, and 0% of genetic studies. Withdrawn (n = 486) and suspended (n = 414) interventions did not provide results. The percentage of studies with results varied from 0% to 21% among different sponsors. The first studies with results were completed in 1992. The proportion of studies with results increased over time. Completion dates were not available for 7446 studies. The database does not have fields available to facilitate routine analysis of the rate of compliance with federal law for posting results. The analysis of accuracy of the protocols in relation to the results and publications is not possible without time-consuming evaluation of individual postings and individual publications.
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